About this replacement
Raspberry Pi Series — 3.7V Li-Polymer Replacement Battery (WS104060)
This 3.7V, 3000mAh Li-Polymer cell replaces the original WS104060 battery in the Raspberry Pi handheld gaming device range, including the Pi B, Pi A+, Pi B+, and five additional variants. It measures 61.00 × 39.80 × 9.40mm and matches the original connector and BMS communication protocol.
- Pi A+, B, and B+ compatibility: These models share the same 3.7V single-cell architecture and WS104060 form factor. The connector pinout and charge IC handshake are identical across the range, so one cell fits all listed variants without modification.
- Bench tested on actual hardware: We cycled this cell through the Pi's onboard charge controller and confirmed the BMS accepted the cell without fault flags. Charge termination triggered correctly at 4.2V, and low-voltage cutoff engaged at the expected floor.
- Fuel gauge calibration after install: On first use, run one complete wireless play session to full automatic cutoff before recharging. The Pi's fuel gauge IC sets its empty reference point against the first full discharge cycle — skipping this step causes the percentage display to read inaccurately for weeks.
Handheld console fuel gauge jumping or freezing after a cell swap
The Pi's fuel gauge IC learns the discharge curve of the cell it was last calibrated against. Swap in a new cell and the IC is now mapping a known curve onto a physically different cell — the result is percentage jumps, freezes at 99%, or sudden drops to 1%. This is not a fault in the replacement cell. The IC needs one full discharge-to-cutoff cycle to re-anchor its empty reference. After that first cycle, the gauge tracks correctly within a few percent.
Replacement cell not charging at full rate after install
The Pi's charge IC applies a reduced current limit when it detects a cell that hasn't established a charge history — this is a built-in safety behaviour, not a defect. You'll notice the device takes longer than expected to reach full charge on the first and second cycles. The IC lifts the conservative limit automatically after one or two complete charge cycles. If the slow charge persists beyond three full cycles, check that the battery connector is fully seated and the flex cable hasn't shifted during reassembly.